A guideline recommends care; a clinical trial tests treatments in people. Avenell and colleagues (online June 26, 2022; 2024 issue) assigned 88 selected reviews or guidelines citing 27 retracted trial reports by chance to different author/editor alert groups. All groups were assigned alerts; 86 publications were emailed, with replies concerning 44. Within one year, nine took public action: three notices, five letters and one retraction. Five actions were unlinked from the original citing publication. An increase in public notification from extra recipients was not demonstrated. Neither replies nor notices guarantee accurate reassessment. Without a no-alert group, the study cannot estimate alerts versus no alerts.